Spark plug



Aug. 28, 1923.

F. VARONE SPARK PLUG Filed June 24. 1920 /N VEN Tale:

, TTYS.

Patented Aug. 28, 1923.

UNITED STATES -FREDERICK vARoNE, or BOSTON, MASSACHUSETTS, ASSIGNOR `oF'oNE-HALF.- To i CHARLES r. GARLAND, or BCSTON,`MASSACHUSETTS.

' SPARK 'y PLUG.

Application led June 24', 1920. Serial No. 391,449.

T0 all uf/wm t may concern Be it .known that I, FREDERICK VARONE, a

citizenl of the United States, residing at.

Boston, in the county of Suffolk and State of "Massachusetts, have invented newV and useful Improvements in Spark Plugs, of

which the following is a specification.

The chief object of this invention vis to provide a spark plug withimproved means whereby a cleansing iiow of air through the spark gap is induced, to cleanse the electrodes at the spark gap from deposits of carbon and other foreign matter, during the suction stroke of the engine.

ments Ywhich I will now proceed yto describe i and claim.

Of theaccompanying drawings forming a part of this specitication,- Y

Figure 1 is a. top plan view of aspark plug embodying the invention.

Figure 2 is a section on line 2 2 of Figure 1.

Figure 3 is an enlargement of a portion of Figure 2.

Figurefi is a view similar to Figure 3, showing the air passage closedv by pressure of gases caused by the compression stroke of the engine.y y

Figure 5 is a section on line 5-5 of Figure 3. e p

Figure 6 is asection on line 6 6 of'Figure 2. `Figure 7 is a sectional view, showing the shell and stopper separated, the other parts of the plug being omitted.

The same refe-rence characters indicate the same parts in all of the figures.

In the drawings, 12 represents a metallic shell having a tubular externally threaded neck 13, adapted to be engaged with the wall of a combustion chamber, said neck forming a grounded electrode of annular. form, the'V inner surface of which is 11.16` of the neck. `A l 15 represents a conducting electrode, which has a preferably spherical head, formed on a rod 16, of conducting material. The rod 16 extends through an insulating formedby theV bore sleeve 17 of porcelain, or other suitable material, and has a shoulder 18 bearing on an kinternal shoulder in the sleeve 17. Thein-r sulator has an, external annular shoulder 19, which is confined by an annular nut 20, en-

The invention is embodied in the improvegaged with an internal thread in the outer portion of the shell. V l

A nut 21 engaged with the threaded outer end portion of the rod 16 is seated on the vouter end of 4the insulating sleeve. The sleeve 17, annular nut 20,-and outer nut 21 constitute-suitable means `for securing the conducting electrode to, andV insulating it from the shell. Idonot, however limit myself to the means described for this purpose.

VThe conducting electrode 15 is supported Vsubstantially concentric with the neck13, the said electrode and aportion of the bore 14 surrounding said head, forming not only an annular spark gap, but also the walls of a constricted passage portion, the'function of which will appear hereinafter.`

The shell is providedwith an air passage communicating with they bore 14:, above the Yspark gap, said passage including a valve chamber in which ak ball valve is loosely Y movable, saidchamber having a valve seat at one side, and an air-conducting valve rest at the opposite side, the arrangement being such that the valve ifs-adapted to be forced against its seat by gas pressure in the neck bore, so that the air passage is closed during the compression stroke of the engine, and is separated from the seat and bears on the valve rest when suction is exerted in the neck bore, to permit a cleansing flow of air through the spark gap during the suction stroke. y

The vpreferred construction whereby the Vair passage and valve chamber are providedl is nextdescribed.

The Shell 12 is provided at one side with a vertical rib 22, containing a tapped socket 23, extending from the. upper end partly to the lower end of the rib. A horizontal duct portion 24 is bored'in the shell below the socket 23, and is connected with the lower end of the socket 23 by a vertical duct por#V tion 25 of smaller diameter than the socket. An annular shoulder or ball rest 26 is yformed bythe intersection of the duct portion 25 with Ithe lower end of the socket, said rest supporting a ball valve 29 and being notched to permit air to pass 'by the valve. The duct portion 24 enters the neck bore 14 at a point above `the spark gap. The duct portion 24 is originally bored through the n rib 22, andl its outer end is subsequently closed by a stopper 28. The duct portion 25 is bored as a. continuation of the socket 23. 30 represents a tubular screw engaged With the socket 23, and having a cupped inner end 3l., located above the ball rest 26, said cupped end constituting a seat for the ball valve 29.

The lower portion of the socket 23, the valve rest 26, and the valve seat 31, 'form a valve chamber, in which the valve 29 is loosely movable, the valve beingf supported by the rest 26 above theI angular duct formed byi the portions 24 and 25.

During the suction stroke of the engine the valve occupies the position shown by Figures 2, 3, and 5, so that a cleansing7 flow of air is induced 'through the air passage and the neck bore 141, the air forcibly ini-- pingingf upon the Walls of the above dev scribed constricted passage portion, and effectively removing all accumulations of carbon, and other foreign matter, from the spark gap.

Duringv the compression stroke of the engine, the valve 16 is held against the seat 3l, so that the air passage is closed, as shown by Figure 4. f

It will be seen by reference to Figure 7, that the shell may be provided with the described air passage and valve chamber by a few simple operations, including the boring,r of the duct portion 24, the boring and tapping of the socket 23, `the boring of the duct portion 25, the grooving oit the valve rest 26, the insertion of the stopper 28, and the insertion of the tubular screw 30.

I clainr:

A spark plug comprising a tubular shell composed. of an externally threaded inner portion, an enlargement above the inner portion, and a vertical rib formed on one side ol said enlargement, the shell being,r provided With a tapped vertical socket in said rib, a horizontal duct portion extending lthrough the lower portion of said rib to the bore of the. shell, and a vertical duct portion extending from the bottom of said socket to the horizontal duct portion, said bottom being of greater diameter than the vertical duct portion, and provided with grooves, so that the bottom forms an annular airconductingvalve rest; a tubular screw engaged with said socket, and having,r a cupped inner end located above the valve rest and forming a downwardly 'facing' valve seat; a ball valve movable vertically between said rest and seat; and a stopper closing the outer end of the horizontal duct portion, the shell being provided with a conducting electrode, and with means for securing the latter tn and insulating it 'from the shell.

In testimonyi whereof' I have ailixcd my signature.

FREDERICK VARONE. 

